1. Field of the Invention
This invention relates to a reclining chair having a seat and a back rest, each of which has an adjustable inclination, a base comprising a vertically adjustable column and a seat carrier, which is supported by the column and has a forward end to which link means, which carry the seat are pivoted by a first pivot, also comprising a second pivot, by which said link means are at their rear end to the back rest, and shifting means for shifting the chair from a position for work, in which the seat is approximately horizontal and includes an angle of about 90.degree. with the back rest, to a position for reclining, in which the seat is rearwardly inclined and includes an obtuse angle with the back rest, and to at least one intermediate position, which shifting can be effected in that a pivotal movement is imparted to the back rest by an occupant, wherein locking means are provided to lock the chair in any of said positions and the shifting from the position for reclining to the position for work is assisted by spring means.
2. Description of the Prior Art
A reclining chair of that kind is known from DE 36 35 044 Al (corresponding to U.S. Pat. No. 4,848,837) and comprises synchronizing levers for constraining the seat and the back rest to perform angular movements through angles having a ratio of 1:2.5. That known chair is adapted to be locked in all adjusted positions by means of a set of disks, which are compressed to be in frictional contact with each other by thrust pins extending through said disks. The pivotal movement of the back rest toward the rear is limited by the largest possible displacement of the center of gravity during the movement from the position for work to the position for reclining and there will be a risk of a tilting of the chair if the center of gravity is displaced further.
Similar remarks are applicable to a known reclining chair which is of a comparable kind and in which the angular movements performed by the seat and the back rest during a shift from the position for work to the position for reclining have a ratio of about 1:2 (WO 86 00508 (corresponding to U.S. Pat. No. 4,693,514)--FIGS. 6, 6a).
In another reclining chair known from DE 37 35 256 Al the problem that the pivotal movement of the back rest to the rear must strictly be limited to avoid a tilting of the chair has not been solved too. In that chair it is merely possible to lower the rear portion of the seat and to incline the back rest, which is connected to the seat. During a change of the inclination of the back rest the forward portion of the seat virtually retains its previous inclination and previous elevation.
Similar remarks are applicable to another reclining chair which is known from German Utility Model 88 06 835 and in which a seat is pivoted to a bracket, a back rest is linked to the bracket by a lever, and said seat and said back rest can be inclined to the rear without a relative movement between the clothes of an occupant and the back rest.
It is also known from Published European Patent Application 0 309 804 that a pivot provided adjacent to the forward edge of the seat of the chair can be horizontally displaced. In that chair the subassembly consisting of the seat and the back rest is pivoted to the rear end of side arms, which define a center of gravity that is disposed at or close to the center of gravity of the chair when the latter is occupied. That chair cannot be provided without arm rests.
It is also known that the seat and the back rest can be swung to the rear with an overproportional pivotal movement of the back rest whereas the forward pivot of the seat is moved rearwardly in an almost horizontal guide (DE 33 22 450 Al).